Search PubMed⌕ Search

Biomedical subjects

S W Hong

Publications and source records attributed to S W Hong.

62 records · Page 4Linked to original sources
PubMed1981

Inhibition of excision-repair of ultraviolet damage in human cells by exposure to methyl methanesulfonate.

Unscheduled DNA synthesis and excision of pyrimidine dimers in human cells exposed to ultraviolet let were inhibited by exposure to methyl methanesulfonate (MMS, 1-2 mM), but repair of MMS damage was not inhibited by UV light. Because the pathways for excision of pyrimidine dimers and alkylation damage have previously been shown to be different, this observation implies a direct effect of alkylation on repair enzymes. We estimate that if inhibition is due to protein alkylation, the UV repair system must present an extremely large target to alkylation and may involve a complex of protein subunits in the order of 1 million daltons such that 1 or more alkylations occur per complex at the concentrations used. These results also indicate that the method of exposing cells to 2 DNA-damaging agents to determine whether they are repaired by common or different pathways can be quite unreliable because of other effects on the repair systems themselves.

Animals↗
PubMedDate not supplied

Focal eosinophilic infiltration of the liver: a mimick of hepatic metastasis.

We present three cases of focal eosinophilic infiltration in the liver that mimicked hepatic malignancy on computed tomography during hepatic arteriography (CTHA) and computed tomography during arterial portography (CTAP). In all patients, focal eosinophilic liver infiltration appeared as a solitary nodule or as two nodules without hepatosplenomegaly and showed homogeneous hyperattenuation on CTHA and hypoattenuation on CTAP.

Diagnosis, Differential↗
PubMedDate not supplied

The key role of the transforming growth factor-beta system in the pathogenesis of diabetic nephropathy.

Progressive renal injury in diabetes mellitus leads to major morbidity and mortality. The manifestations of diabetic nephropathy may be a consequence of the actions of certain cytokines and growth factors. Prominent among these is transforming growth factor-beta (TGF-beta) because it promotes renal cell hypertrophy and stimulates extracellular matrix accumulation, the two hallmarks of diabetic renal disease. In cell culture, high ambient glucose increases TGF-beta mRNA and protein in proximal tubular, glomerular epithelial, and mesangial cells. Neutralizing anti-TGF-beta antibodies prevent the hypertrophic and matrix stimulatory effects of high glucose in these cells. In experimental and human diabetes mellitus, several reports describe overexpression of TGF-beta in the glomeruli and tubulointerstitium. We demonstrate that short-term treatment of diabetic mice with neutralizing monoclonal antibodies against TGF-beta significantly reduces kidney weight and glomerular hypertrophy and attenuates the increase in extracellular matrix mRNAs. Long-term treatment of diabetic mice further improves the renal pathology and also ameliorates the functional abnormalities of diabetic nephropathy. Finally, we provide evidence that the renal TGF-beta system is significantly up-regulated in human diabetes. The kidney of a diabetic patient actually elaborates TGF-beta1 protein into the circulation whereas the kidney of a non-diabetic subject extracts TGF-beta1 from the circulation. The data we review here strongly support the hypothesis that elevated production or activity of the TGF-beta system mediates diabetic renal hypertrophy and extracellular matrix expansion.

Animals↗
PubMedDate not supplied

Overexpression of c-ErbB-2 protein in gastric cancer by immunohistochemical stain.

An immunohistochemical stain to the c-ErbB-2 protein was performed in 225 paraffin-embedded tissue blocks from patients with locally advanced gastric cancer who underwent curative resection. The overexpression of the c-ErbB-2 protein was observed in 27.4% of the patients. The c-ErbB-2 positivity showed a statistically significant correlation with nodal status and stage. The patients with an overexpression of the c-ErbB-2 protein had a tendency to a shorter survival than those without, but it was not statistically significant (p = 0.08). The 5-year survival rate after surgery was 54% in the negative staining group to the c-ErbB-2 protein and 49% in the positive staining group. This suggests that the c-ErbB-2 protein has a possible role in lymph node metastasis. Therefore overexpression of the c-ErbB-2 protein is a useful indicator of disease progression in gastric carcinoma patients who received curative surgery.

Adult↗
PubMedDate not supplied

Preventing nosocomial Mycobacterium tuberculosis transmission in international settings.

Tuberculosis (TB) is a worldwide disease, and nosocomial transmission is known to occur. Authoritative preventive guidelines such as the one developed by the Centers for Disease Control have been published, but the expenses for implementing them can be prohibitive. Each country needs to develop its own protocol to prevent nosocomial transmission of TB. This article describes the key elements of a protocol undertaken for all public hospitals in Hong Kong, where TB is endemic.

Communicable Disease Control↗